1. Field of the Invention
This invention relates to floor cleaning machines, in particular carpet cleaning machines, in the form of a brush vacuum cleaner with a motor-driven brush roller, which is located in a brush set with wheels facing the floor. The height of the brush roller can be adjusted to the current working conditions, such as pile height and brush wear, as the height of at least one wheel, can be adjusted to position the brush roller in relation to the floor
2. Description of the Prior Art
Floor cleaning machines of this type are known to be an effective way to clean carpets. A distinction is made in the field of vacuum cleaners between machines with a motor which simultaneously vacuums and drives the brushes, and so-called two-motor machines. The prior art includes such brush vacuum cleaners in which the brush function is electronically monitored, by using the power absorbed by the brush drive motor as a measured variable. The electronic circuitry thereby indicates by means of a display whether the motor is operating under normal load or with a load which is below or above a specified threshold. An indication is thereby given whether the brush roller is sufficiently engaged in the carpet pile to obtain an effective cleaning. If it is not, the brush is reset by a manual adjustment of the wheel or of the brush roller itself, so that an optimal setting can be obtained.
In commercial applications, in particular in cleaning different types of carpets, the height must constantly be adjusted to obtain an effective cleaning. But in practice, such adjustments are made only to a limited extent.